A 22-week half-ironman training regiment is sufficiently long to develop the stamina you need in order to swim 1.2 miles, bike 56 miles and run 13.1 miles. For this 70.3-mile race, ironman training is a matter limiting what you do as much as maximizing your training. Overtraining -- endurance being the key to completing a half-ironman -- can prevent you from finishing the race. Training for a half-ironman is a matter of knowing what to do and when.

Foundation

Step 1

Develop a base endurance foundation for the first 14 weeks of the 22-week program. Train 10 to 14 hours the first week. The amount you train the first week depends on your beginning endurance capacity. Increase the time you train by 10 percent each of the next three weeks.

Step 2

Divide your training time in proportion to each leg of the race. On average, biking takes up 50 percent of a competitor's race time, running takes up 38 percent and the swimming leg takes up 12 percent.

Alternate events during the foundation-training stage every day. Do not train for every leg of the race every day. Allow your body's different muscle groups time to recover, even though you are training five out of every seven days.

Step 3

Reduce your training time by half at the beginning of week four. Allow your body to recover from the first three weeks of base training. If possible, train each leg of the race every day during your recovery week.

Return your training volume to week two's length at the end of your recovery week. Again, only train for one leg of the race each day when building your stamina foundation.

Step 4

Every week for the next three, increase the volume of your training by 10 percent, -- just as you did the first month -- then take a recovery week during which you reduce your training time to that of week six. Complete a total of three base-building cycles, then move on to the construct stage.

Build, Peak, Rest

Step 1

Shock your system with a build training phase. Decrease the amount of time you train, but increase the intensity. Average the length of time your train week 13 with the length of time you trained in week two and during the build training phase, and train that amount but increase the speed at which you bike, swim and run.

Step 2

Maximize your intensity and reduce your training volume by 30 percent of your build training phase to make your body peak. Push yourself hard during this phase but do not overtrain. Continue this training until two weeks before the race.

Step 3

Commit to a rest phase. The week before the race, train between seven and 10 hours. Keep the intensity high the entire week but rest the two days before the race and do not train at all.